In a related structure, the output voltage of a power supply apparatus including a switching element may be controlled by changing a duty ratio of switching of the switching element in the power supply apparatus. In another related structure, the output voltage of a direct current to direct current converting device including a switching element may be controlled by changing a duty ratio of switching of the switching element in the direct current to direct current converting device.
Related art is disclosed in Japanese Laid-open Patent Publication No. 06-351244 and Japanese Laid-open Patent Publication No. 2003-92880.